RAID Controllers — Dell PERC vs HPE Smart Array vs Broadcom MegaRAID
The three RAID controller families you meet in Dell, HPE and white-box servers are closer cousins than the badges suggest — Dell PERC and HPE's MR line are both built on Broadcom MegaRAID silicon. Here is how they line up, and what to check when buying refurbished.
What a RAID controller actually is
A RAID controller is a card (or on-board chip) with three parts that matter: a RAID-on-Chip (RoC) processor that computes parity, a DRAM write cache that makes writes fast, and a battery or flash module that protects that cache if the power drops. It presents drives to the operating system as logical volumes and offloads parity from the host CPU. Modern tri-mode controllers speak SAS, SATA and NVMe from the same ports.
Side by side
| Dell PERC 12 (H965i) | HPE SR932i-p / MR416i-p Gen11 | Broadcom MegaRAID 9560-16i | |
|---|---|---|---|
| Silicon | Broadcom SAS4116W RoC | SR: Microchip SmartROC; MR: Broadcom MegaRAID | Broadcom SAS3916 RoC |
| Host bus | PCIe Gen4/Gen5 ×16 | PCIe 4.0 ×16 (SR932i-p) / ×8 (MR416i-p) | PCIe 4.0 ×8 |
| Device speeds | SAS 6/12/22.5 Gb/s (24G); NVMe Gen3/4/5 | 24G SAS; NVMe (tri-mode) | 12 Gb/s SAS; PCIe Gen4 NVMe (16 GT/s) |
| Cache | 8 GB DDR4-3200 | 8 GB | 8 GB |
| Cache protection | Battery-backed (BBU) | Flash-backed (FBWC) | CacheVault CVPM05 (flash) |
| RAID levels | 0, 1, 5, 6, 10, 50, 60 | 0, 1, 5, 6, 10, 50, 60 | 0, 1, 5, 6, 10, 50, 60 (+ JBOD) |
| Max devices | Backplane-dependent | Up to 238 with expander (SR932i-p) | 240 SAS/SATA; 24 NVMe |
| Management | iDRAC, PERCCLI | iLO, Smart Storage Administrator / StorCLI | LSI Storage Authority, StorCLI |
| Server family | PowerEdge 16G/17G | ProLiant Gen11 | Vendor-neutral / white-box |
Dell's earlier PERC 11 (H755, H750, H355, H350) supports the same RAID 0/1/5/6/10/50/60 set and adds NVMe depending on the backplane.
The families in one line each
- Dell PERC (PowerEdge RAID Controller): Dell's tuned rebadge of Broadcom MegaRAID silicon, managed through iDRAC. PERC 12 (H965) moved to 24G SAS and PCIe Gen5.
- HPE: two lines — SR (Smart RAID, on Microchip SmartROC silicon, the classic "Smart Array" heritage) and MR (MegaRAID/Broadcom silicon). Both cover RAID 0/1/5/6/10/50/60 and are managed through iLO.
- Broadcom MegaRAID: the merchant-silicon original (LSI heritage) found in Supermicro and white-box servers, managed with LSI Storage Authority or StorCLI.
Cache protection is the part that matters
The write cache is what makes hardware RAID fast — but only while its backup unit is healthy. When the battery (BBU) or supercapacitor/flash module (FBWC, or Broadcom's CacheVault) is dead or missing, the controller drops to write-through and write performance collapses. On any refurbished server this is the single most important thing to verify.
Buying refurbished — the checklist
- Confirm the cache-protection module (BBU / FBWC / CacheVault CVPM05) is fitted and reporting healthy — not "learn cycle", degraded or failed.
- Remember arrays are tied to a controller family. Moving disks to a different controller usually means importing a "foreign configuration"; moving across makes can mean data loss. Preserve the drive order.
- For ZFS/TrueNAS or software RAID, you need the card in HBA/IT (pass-through) mode, not RAID mode — check it can run IT mode.
- Match tri-mode/NVMe capability to the backplane and to the drives you plan to run.
- Match PCIe generation and lane width (×8 vs ×16) to the slot.
Specifications are drawn from Dell, HPE and Broadcom product documentation and vary by exact model.
Enterprise storage and drives, priced in rand:
Sources
- Dell PERC 11 User's Guide — summary of RAID levels
- Dell PowerEdge RAID Controller 12 (PERC 12) User's Guide
- Broadcom MegaRAID 9560-16i
- HPE Smart Array / MR Gen11 controllers
- HPE Gen11 storage controllers overview
Compiled by the Server Hub newsroom from the reporting above. Every factual claim is checked against those sources before publication, and every source is linked so you can verify it yourself. How we work.
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